Mechanism for releasing molded articles from molds



June 27, 1950 sULLlVAN r 2,513,216

MECHANISM FOR REL-EASING MOLDED ARTICLES FROM HOLDS Filed June 4, 1947 2 Sheets-Sheet 1 f? I E 26 l x5 l1} 1'9 I l 21 l 'i llll lill m 2 3mm "'illilllll fi WI H I [L CDMPER mmw June 27, 1950 E. J. SULLIVAN EI'AL 2,513,216

; uacwmxsu FOR RELEASING momma ARTICLES FROM MOLDS Filed June 4, 1947 2 Sheets-Sheet 2 Bid-SULLIVAN u'tZDRAPIR Patented June 27, 1950 MECHANISM FOR RELEASING MOLDED ARTICLES FROM MQLDS Emmet J. Sullivan, Toledo, Ohio, and JamesC;

Draper, Qttawa Lake, Micln, assignorsv to Owens-Illinoie-Glass Gompany, a corporation of Ohio- Application June 1 1947; SerialNo. 752,310-

8-Claims. (01 18-20) 0.111. invention relates to apparatus for molding articles. and particularly to mechanism for releasing; the molded articles from a molding element, The in ention. is adapted for use in mold.- i-ng hollow articles such as capsused; as closures for-bottles, jars and. the like.

machine and method of operation.-

the present invention is: applied, the section be- In form herein illustrated, the invention is ing atthe line l-l-on Fig.3; shown. as applied: to a Lauterbach type of; mold Fig. 2 is a front elevation of the upper. portion ing machine such as disclosed, for example, in ofone'ofthe-molding-units; the. patent to. Lauterbach, #2,155,3l.fi, April 18, Figs 3? is a fragmentary part sectional plan 1939., Machine for Molding Plastic Materials. view; showing theannular series of molding Such machine, as shown and. described, is used units;. for molding internally threaded caps. The Figs. 4, B andt-are sections at the lines l4; molding compound: is, an organic plastic of the 5-5 and'B -G respectively, on Fig. 3, said-secthermosetting type andis subjected to heat and 5 tions: being takenthrough successive units, and pressure. within the electrically heated mold and thereby showing: success-ive'steps in the operais thereby polymerized or reacted so that the tion of loosening andremoving' a molded article molded article sets. or hardens within the hot fromtlie molds. mold, After the. article is thus hardened, it. is The machine comprises aearriagelflon which removed from the mold by first withdrawing the ismounted an annular series of molding units H; outer diemember, leaving the moldedarticlein Thecarriage ismounted for: rotationina sta position. on the inner screw-threaded die memtionary framework-comprising an annular housher; orplug, and thereafter unscrewing it. from ing [2 surrounding the series of molding units the plug. Reference may be had. to the above and surmounted. by av cover plate l3 bolted mentioned. patent for a full disclosurev of such thereto.

Each m'oldingunit comprises a female die l4 It. isfound; that with such. method of mold.- formedwithan upwardly opening moldcavity, ing wherein the lower-0r; outer die is-withdrawn'. and a male die oriplugltl; The latter'is formed from the molded article, leaving the latter with a-screwrthread: lliifor molding'a'correspondtightly held: in position on the heated plug, the ingscrew threadwithinathecap: H; The lower;- heatsupplieol from the plug tends to expand the. die Mt isicarried on ahydraulic-plunger 53 which molded; cap outwardly. Also, the pressure. of is. mounted. for; up-.and-.-down. movement in the the confined gas, incident to the molding andv carriagezlllz The'upper dienl5u is attachedby a curing operation, builds up a pressure tending; coupling,;slee.ve20:;tothe-lower end'ofa vertical to. cause doming of the article andthere is also. shafton spindle li9.',,,the. shaft andcouplingbea1 tendency to blistering; and explosion of the ing; journalledi for rotation within the frame molded" piece. An objectof; the present-inven- Ill; The: shaft. extends-.- upwardly through a tion is to overcome these objectionable features tubular; bearing. 21; flanged; and bolted to the and to this end there is provided means by which carriage; Mounted on the; bearing. member 21 t t d d-plug is automatically loosened from; 40 for. oscillating-- movement about the axis of the the: molded. cap, by. partially unscrewing itfromv shaft l9.--is a-.r0cker;22.- Keyed to the shaft IS.- the cap. as. the lower die is withdrawn. Suchaboverthesaid-rockerris-a-pinion 23. The rocker operation removes the molded cap from intimate. 2 2lis;formed'iwith a segmental raclr 2l1concentric contact with. the source of heat which tends to with the-shaft l9 and running in mesh with the; expand it, outwardly, thereby reducing the eX:.- 45. pinion 23iofthe-nextradjoining unitpansion. It further provides clearance through Mountedmn-thebearlng member. 2-! is a rock; which. the confined, gas may escape, thereby, rearm.25 .-abo.vethe-rocker Hand adaptedzfor rock.- lieyingthepressure. Further, the tendency: of" ing; movements relative to-the rocker 22, limited the cap'to expandcan proceed in,two directions in one direction by a stop lug 26 formed on-the asit is no longer limited by the plug. This; re-

duces the. degree. and efiect of: expansion. The loosening of the molding lug; eliminates or minimizes, the doming; or bulging of the; cap and; also preventsv blistering and explosionyof the.

moldedie e.

2.. Other. objects. of the invention will appear hereinafter.

Referring to the=accompanying drawings:' Fig. 1. is. a sectional elevation of a portion of a.Lauterbach type of. molding machine to which a-rm 2.5r'and; projecting into the path of the rocker 22. The rocker- 22 and: rock. arm 251areyieldably held insuch relative positionbyacoil compression. spring; 23!. interposed therebetween.

Therockingg movement .of the. rocker 2 2. is limited as. by a. stop 28.: attached to the; bearing! memben 3 2i and extending upwardly between stop surfaces 29 and 30 on the rocker 22.

Each rock arm 25 is rocked inwardly by a stationary cam 3| (Figs. 1 and 3) extending circumferentially of the machine and on which runs a cam follower roll 32 on the rockarm. This rocking movement operates to compress the spring 21 as hereinafter described. A second cam 33 is mounted on the machine frame in position to engage the rockers 22 for swinging them outwardly together with the rock arms 25.

The operation of loosening a molded cap on the screw plug and removing the cap from the dies takes place while the molding unit is trathe unit at position 12, thereby compressing the coil spring 21 and, through the rack and pinion, applying a turning force to the plug I5.

During the travel of the molding unit from posi-. tion a to position b, the plunger l8 of said unit commences its downward movement, thereby releasing the upward pressure on the plug and molded cap so that the compressed spring 21 is permitted to expand and rotate the plug in a direction to partially unscrew it from the molded .cap. The unscrewing movement of the plug is limited by the stop lug 26 in the path of the rocker 22 so that as the plunger [8 continues its downward movement, the cap is left loosely supported on the plug. The loosening of the plug serves to relieve the gas pressure developed during the molding and curing or setting of the cap and also permits a uniform expansion of the cap, preventing distortion and moreover, reduces the heat transfer from the plug to the molded cap, owing to the less intimate contact of the plug with the cap, thus further reducing the heating and expansion of the cap.

As the molding unittravels from position b to position c, the plunger [8 is withdrawn entirely from the molded cap and the latter brought into contact with the disk 34 mounted on the shaft 35 and rotating as indicated by the arrow, Fig. 3, in a direction to unscrew the cap and discharge it into the chute 36 (Fig. 6). The cap IT, as shown in Fig. 6 may have its exterior peripheral surface roughened or formed with corrugations 38 or the like. These serve, in the first place, to prevent rotation of the molded cap within the mold I4 when the plug is rotated. They also prevent slipping of the cap on the disk 34 and provide a gripping surface for the cap when in use.

As the molding unit travels from the position c to position d, the cam 33 swings the rocker 22 outwardly, the latter also swinging the rock arm 25. This movement of the rocker operates through its gear to rotate the pinion and thereby reset the attached molding plug for a succeeding operation.

Modifications may be resorted to within the spirit and scope of our invention.

We claim:

1, A molding machine, comprising a carriage mounted for rotation about a vertical axis, a molding unit mounted on the carriage for rotabeing rotatable about its own axis, a rock arm connected to the last mentioned element, a spring,

"means for moving said rock arm against the action of said spring and thereby applying a torque to said rotatable element insuificient to cause its rotation while said elements are held together by said pressure and operable automati ically to rotate said rotatable element when said pressure is relieved.

2. A machine for molding hollow internally screw-threaded caps, said machine comprising a carriage mounted for rotation about a vertical axis, a plunger mounted on the carriage for upand-down movement, a mold mounted on the plunger and formed with a mold cavity opening upwardly, a molding plug mounted on the carriage above and in alignment with said mold cavity and positioned to enter the mold cavity when the plunger is moved upward, said plug formed with an exterior spiral thread for molding a thread on the cap as the latter is formed in the mold, a spring mounted to rotate with the carriage, a stationary cam, means operated by said cam to apply pressure to said spring when the mold reaches a predetermined position during its rotation with the carriage, means for transmitting the spring pressure to the plug and thereby applying a torque to the plug, said torque being applied in a direction for unscrewing the plug from the molded article, said cam being extended concentrically with the carriage a predetermined distance and thereby maintaining said torque during a predetermined length of travel of the plug. r

3. A machine for molding hollow internally screw-threaded caps, said machine comprising a carriage mounted for rotation about a vertical axis, a plunger mounted for up-and-down movement on the carriage, a mold carried by the plunger and formed with a mold cavity, a molding plug mounted on the carriage in alignment with said mold cavity, said mold and plug being relatively movable to and from a mold closing position in which the plug is positioned within the mold cavity, said plug having a spiral molding surface thereon, a shaft connected to said plug, a pinion on said shaft, a rack in mesh with said pinion, a stationary cam, and means operated by said cam for applying spring pressure to said rack in a direction to rotate said pinion and thereby rotate the said plug in a direction for unscrewing it from a cap in the mold.

4. machine for molding hollow internally screw-threaded caps, said machine comprising a carriage mounted for rotation about a vertical axis, an annular series of molding units mounted on the carriage for rotation therewith, each said unit comprising a mold formed with a mold cavity and a molding plug adapted to enter said cavity, said plug formed with a spiral molding surface, a shaft connected to each plug for rotating it, pinions on said shafts, rockers individual to said shafts and each mounted for rocking movement on its said shaft, each said rocker formed with a segmental rack running in mesh with the said pinion of an adjoining molding unit, and automatic means for rocking each said rocker as the carriage rotates.

5. A machine for molding hollow internally screw-threaded caps, said machine comprising a carriage mounted for rotation about a vertical axis, an annular series of molding units mounted on the carriage for rotation therewith, each said unit comprising a mold formed with a mold cavity and a molding plug adapted to enter said cavity, said plug formed with a spiral molding surface, a shaft connected to each plug for rotating it, pinions on said shafts, rockers individual to said shafts and each mounted for rocking movement on its said shaft, each said rocker formed with a segmental rack running in mesh with the said pinion of an adjoining molding unit, rock arms individual to said molding units and mounted on said shafts for rocking movement, compression springs interposed between said rockers and rock arms, and a stationary cam positioned and arranged to rock said rock arms and compress each said spring when the carriage reaches a predetermined position and thereby apply a torque to each said spindle as it reaches a predetermined position.

6. A molding machine, comprising a carriage mounted for horizontal rotation, molding units mounted on the carriage for rotation therewith, each said unit comprising a plug with a spiral molding thread, vertical shafts journalled in the carriage to which the plugs are connected, pinions on said shafts, a pair of rocking elements mounted on each shaft, said elements being relatively rotatable, a coil compression spring interposed between the said elements of each pair, one said element comprising a rack running in mesh with the pinion of the next adjoining unit, and a stationar cam arranged to rock one said element of each pair in a direction to compress the said interposed spring.

7. A molding machine, comprising a carriage mounted for rotation about a vertical axis, molding units mounted to rotate with the carriage and arranged in an annular series concentric with said axis, each said unit comprising'a vertical shaft journalled for rotation on the carriage, a molding element attached to each said shaft for rotation therewith, rockers individual to said units, each mounted for rotation about the axis of the said shaft, means providing a driving connection between each rocker and the shaft of the next adjoining unit, a stationary cam and means actuated thereby for swinging said rockers in one direction, and means for swinging said rockers in the opposite direction.

8. A molding machine, comprising a carriage mounted for rotation about a vertical axis, molding units mounted to rotate with the carriage and arranged in an annular series concentric with said axis, each said unit comprising a vertical shaft journalled for rotation on the carriage, a molding element attached to each said shaft for rotation therewith, pairs of rocking elements individual to said shafts and mounted for oscillating movement on said shafts, means providing a driving connection between one said element of each pair and the next adjoining shaft, a stationary cam in the path of one rocker of each said pair operable to swing said rocker in one direction, compression springs interposed between the rockers of each pair, and a second stationary cam positioned in the path of the other rockers of said pairs, said cams being positioned and arranged to swing the rockers alternately in opposite directions.

EMlVIET J. SULLIVAN. JAMES C. DRAPER.

REFERENCES CITED The following references are of record in th file of this patent:

UNITED STATES PATENTS Number Name Date 1,959,612 Burke May 22, 1934 2,137,539 McIntash Nov. 22, 1938 2,155,316 Lauterbach Apr. 18, 1939 2,371,195 Strauss Mar. 13, 1945 2,404,631 Gronemeyer July 23, 1946 2,409,142 McC'oy Oct. 8, 1946 2,440,367 Crapp Apr. 27, 1948 

